This proposal is in response to an NIMH program announcement on women's mental health in pregnancy and the postpartum period and addresses several goals of the program by investigating the epidemiology, risk factors, and effects of treatment on depression during pregnancy. Ten to fifteen percent of women experience some degree of depression during pregnancy and these women are at higher risk of depression following childbirth and later in life. Maternal depression during pregnancy may have adverse effect on pregnancy and neonatal outcomes, and on-going maternal depression is known to have adverse effects on parenting and family function. To help determine the best course of treatment for depression among pregnant women, this study will analyze provider, pharmacy, and hospital claims data from the Tennessee Medicaid (TennCare) population from 1994-2003. This large population includes over half of all Tennessee births during the study period. The proposed study makes efficient use of existing data and infrastructure to study the relationship of treated and untreated depression on maternal and infant outcomes, which will help guide both future clinical research and current medical practice. The central hypothesis is that there are no measurable harmful effects of pharmacotherapy for depression during pregnancy with regards to specific pregnancy, perinatal, and depression outcomes. To determine whether women who take antidepressants during pregnancy have increased rates of adverse pregnancy and perinatal outcomes, we will perform a retrospective cohort analysis in otherwise healthy pregnant women to evaluate pregnancy and perinatal outcomes by exposure to specific antidepressant medications. We will perform a second retrospective cohort study of women with recognized depression prior to pregnancy. Women will be classified as exposed or unexposed to antidepressants and we will quantify the risks of adverse pregnancy, perinatal, and depression outcomes by antidepressant treatment status after adjusting for markers of depression severity. The second proposed retrospective cohort is an innovative analysis that will use a subset of the very large population to evaluate the relative risks of treating depression during pregnancy. Results of the proposed analysis will help women and their health care providers decide how to manage depression during pregnancy and guide future research. Understanding the impact of treated and untreated depression during pregnancy is very important to public health, specifically the well being of the mother, healthy fetal development, and the development of a healthy mother-infant relationship. [unreadable] [unreadable] [unreadable]